copying data if possible, and avoid copydeprecation warnings.

arrays (e.g. RGB data)

resampleToPixdims and resampleToReference

package). Refactored, cleaned up, and enhanced to accept an arbitrary affine
transform - can be used to resample an image into any other space.

Also made small fixes to trees that contained invalid characters

default to returning a flat list of matches. subtree-related fixes to scan
function

operators to Match class so it can be ordered. Protect Match attributes via
@property

mutate canonical version

for which an optional variable is not present

actually exist on disk (and corrsepond to files).